Note: Javascript is disabled or is not supported by your browser. For this reason, some items on this page will be unavailable. For more information about this message, please visit this page: About CDC.gov.

Q&As About the Options for Protecting Your Child Against Measles, Mumps, Rubella, and Varicella

Information for Parents and Caregivers

To be protected against measles, mumps, rubella (German measles), and varicella (chickenpox), children need to be vaccinated twice: once when they are 12 through 15 months old, and again when they are 4 through 6 years old.

To prevent these diseases, two vaccination options are available. A child can receive two shots: the measles, mumps, and rubella (MMR) vaccine and the varicella vaccine, or one shot: the measles, mumps, rubella, and varicella (MMRV) vaccine.

Questions and Answers:

How do I decide which option to use for my child’s first vaccination against measles, mumps, rubella, and varicella?

Your doctor can discuss using MMR and varicella vaccines or MMRV vaccine with you to help you make an informed decision for your child. There are risks and benefits with each option. For a 12- through 47-month-old child’s first vaccination against these diseases, there is one major trade-off to consider.

Using the MMRV vaccine means that a child will only have to have one shot to provide protection against the four diseases (measles, mumps, rubella and varicella). However, the MMRV vaccine has been associated with a higher risk of two side effects that you should know about when it is used for the first vaccination among children who are 12 through 47 months old.

First, children who get the MMRV vaccine for their first vaccinations are more likely to have fever of 102°F or higher within 42 days of being vaccinated than those who get the MMR and varicella vaccines at the same visit for their first vaccinations. Studies have shown that out of every 100 children who are 12 through 23 months old and get the MMRV vaccine for their first vaccinations, about 22 have fever of 102°F or higher within the 42 days following vaccination compared with 15 out of every 100 who get the MMR and varicella vaccines at the same visit. Most of this increase in fever occurs during the 5 to 12 days after vaccination only.

Second, two studies have shown that children who get the MMRV vaccine for
their first vaccinations when they are 12 through 23 months old are about
twice as likely to have a febrile seizure in the 5 to 12 days following
vaccination compared with those who receive the MMR and varicella vaccines at the same visit. However, it’s important to remember that the overall risk of febrile seizures is very low for both options (about 8 out of every 10,000 children who get the MMRV vaccine for their first vaccinations when they are 12 through 23 months old, and about 4 out of every 10,000 children who get the MMR and varicella vaccines at the same visit for their first vaccinations when they are 12 through 23 months old).

Studies of febrile seizures after vaccination with first dose of MMRV vaccine have not been done in older children, but experts agree that this increased risk of febrile seizures during the 5 to 12 days after the first vaccination with MMRV vaccine likely also occurs in children aged 24 through 47 months, but not in children who are 48 months or older because febrile seizures are uncommon after this age.

For the first dose of measles, mumps, rubella, and varicella vaccines given at ages 48 months and older, using the MMRV vaccine is generally preferred over using the MMR and varicella vaccines because it requires one less injection to provide similar protection with no known additional risks of side effects. See the ACIP Recommendations.

Is there an increased risk of febrile seizures after vaccination with the MMR vaccine?

Among children who are younger than 7 years old, approximately one additional febrile seizure occurs in the 8 to 14 days after vaccination for every 3,000-4,000 children vaccinated with the MMR vaccine, compared with children not vaccinated during the preceding 30 days.

Is there an increased risk of febrile seizures after vaccination with the varicella vaccine?

Studies have not shown an increased risk of febrile seizure after varicella vaccine.

What is the risk of febrile seizures after the first dose of MMRV vaccine compared with the first dose of MMR and varicella vaccines administered at the same doctor visit?

It’s important to understand that both options have a very small risk of febrile seizure as a side effect. For children who get the MMRV vaccine for their first vaccinations when they are 12 through 23 months old, about 8 out of every 10,000 will have a febrile seizure. For children who get the MMR and

varicella vaccines at the same visit for their first vaccinations when they are 12 through 23 months old, about 4 out of every 10,000 will have a febrile seizure.

What is a febrile seizure?

"Febrile" means "relating to a fever." In some children, having a fever can bring on a seizure. During a febrile seizure, a child often has spasms or jerking movements—large or small—and may lose consciousness. Febrile seizures usually last only a minute or two. They are most common with fevers reaching 102°F (38.9°C) or higher, but can also occur at lower temperatures or when a fever is going back down.

What kinds of things can cause febrile seizures?

Febrile seizures may happen with any condition that causes a fever, including typical childhood illnesses like ear infections or even the common cold. Measles was a common cause of febrile seizures in the U.S. before it became a rare disease due to the success of the vaccination program.

Who is most at risk for febrile seizures?

Febrile seizures are not uncommon. About 2-5% of young children will have at least one febrile seizure. Most febrile seizures occur in children between the ages of 6 months and 5 years. The peak age is 14 through18 months, which overlaps with the ages when first doses of the MMRV, MMR, and varicella vaccines are recommended. A child who has already had a febrile seizure is more likely to have another one. Also if a member of a child's immediate family (a brother, sister, or parent) has had febrile seizures, that child is more likely to have a febrile seizure.

How serious is a febrile seizure?

Most children who have febrile seizures recover quickly and have no lasting effects. However, febrile seizures often result in a visit to an emergency room and can be very frightening for parents and caregivers.

About 1 in 3 children who have one febrile seizure will have at least one more febrile seizure. Most children (>90%) will not develop epilepsy. Genetic predisposition and other factors such as cerebral palsy, delayed development, or other neurological abnormalities increase the risk for future development of epilepsy after a febrile seizure.

Two studies have shown that children who have febrile seizures after receiving an MMR vaccine are no more likely to have epilepsy or learning or developmental problems than children who have febrile seizures that are not associated with a vaccine. Experts believe it is likely that this finding for MMR vaccine applies to MMRV vaccine as well.

Is there an increased risk of fever or febrile seizures associated with the MMRV vaccine when it is used as a second dose?

Studies do not suggest that children who are 4 through 6 years old and receive the MMRV vaccine have an increased risk of febrile seizures after vaccination when compared with those who receive the MMR and varicella vaccines at the same doctor visit. In addition, the second dose of MMRV vaccine is less likely to cause fever than the first dose.

How do I decide which option to use for my child’s second vaccination against measles, mumps, rubella, and varicella?

For the second dose given at any age (15 months through 12 years), use of the MMRV vaccine is generally preferred over using the MMR and varicella vaccines because it requires one less injection to provide similar protection with no known additional risks of side effects. See the ACIP Recommendations.

Why is it important that my child be fully vaccinated against measles, mumps, rubella, and varicella?

Measles, mumps, rubella, and varicella are all potentially serious diseases.

Related Pages

Images and logos on this website which are trademarked/copyrighted or used with permission of the trademark/copyright or logo holder are not in the public domain. These images and logos have been licensed for or used with permission in the materials provided on this website. The materials in the form presented on this website may be used without seeking further permission. Any other use of trademarked/copyrighted images or logos requires permission from the trademark/copyright holder...more